Hydrofoil aquatic device



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United States Patent HYDROFOIL AQUATIC DEVICE Casimir James Kregall,Chicago, Ill.

Application January 14, 1955, Serial No. 481,809 8 Claims. (Cl. 9-18)This. invention relates to water vehicles, and has to do with ahydrofoil aquatic device intended for use in water sports. I

My invention is directed to a device of the character stated havinghydrofoils elf'ective for raising the body of the device out of thewater and supporting it during travel at higher speeds and pontoonseffective for supporting the device when travelling at lower speeds orat a standstill. The pontoons are moved. automatically from a raised orsupporting position to a lowered or retracted position and vice versaresponsive to raising and lowering of the body out of and into the waterin accordance with increase and decrease in speed of travel. Thepontoons provide, in either position thereof, Windshields and, when inretracted or lowered position, cooperate with certain elements of thebody to reduce'wind resistance to a minimum when travelling at highspeed and the body is so constructed as to present but little wind,resistance. The pontoons may be locked in either position, to preventinterference when banking or turning, particularly at high speed, andhave fiat inner sides which, when the pontoons are raised or extended,function as hydroplanies. to facilitate travel of the device at thelower speeds with the body submerged. The propelling unit preferably isan outboard motor of known type having a support tube mounted forturning movement in a tubular housing which also provides a support forthe forward hydrofoils, mean-s being provided for turning the motor andits support tube for steering, purposes. Further objects and advantagesof my inventionwill appear from the detail. description.

In the drawings:

Figure 1 is a side view, with certain parts broken away, of a hydrofoilaquatic device embodying my invention;

Figure 2 is a plan view of the device of Figure 1;. I

Figure 3. is a sectional view taken. substantially on. line 3-3 ofFigure 1, with the motor head and the forward pontoons in raisedposition indicated inbroken lines;

Figure 4 is an underneath view of the forward. portion of the devicewith the forward pontoons in retracted or lowered position, the raisedposition of the pontoons being indicated in dot and dash lines and themotor tube housing and the motor support tube therein shown in crosssection;

Figure 5 is a detail of one of the pivot rods and the floats thereon,certain parts being shown .fragmentarily and in section; and

Figure 6 is. .a fragmentary plan view, partly. broken away and insection, of the device .of Figure 1, showing the pontoon latch meansengaged with the forward ponteens and holding them in lowered position,the rearward pontoons being omitted.

The water vehicle of my invention comprises an elongatedrectangularframe 10 having top and bottom members 11 and 12, respectively, securedat their ends to forward and rearward cross members or bulkheads 13 and14, respectively, which project a substantial distance beyond the sidesof members 11 and 12, as shown in 2,748,400 Patented June 5, 1956 Figurel. The frame 10 preferably is constructed of wood,v is of generallyelongated rectangular shape and is of oblong shape in plan and of slightwidth relative to its length, for ready passage through the water. Anose member 15 of generally segmo-spherical shape is secured to theforward bulkhead 13 and a tail member 16, also of generallysegmo-spherical shape but tapering somewhat rearward and downward, is.secured' to the rearward bulkhead 14. The frame and the nose member 15and'the tail member 16 together constitute the body of the vehicle,'therounded nose member 15 and tail member 16 reducing water and airresistance of the vehicle during travel thereof.

Two pivot rods 18 are disposed at opposite sides of frame 10, a shortdistance below and parallel with, top member 11 (Figure 3'), and aremounted at their ends for turning movement in bearing sleeves 19 securedin the bulkheads 13 and 14. A forward pontoon 2t) and a rearward pontoon21, each closed and of generally segmocylindrical shape, are secured oneach of the pivot rods 18. Each of the forward pontoons 26 is provided,at its upper portion, with an inward extension 22 substantiallyconcentric with rod 18 and its inner side wall 23 below such extensionis fiat for the major portion of its extent. The forward ends of theforward pontoons 20 are in close proximity to the forward bulkhead 13and the outer sides thereof are curved conformably to the side portionsof nose member 15 so as to merge smoothly therewith when pontoons 20 arein their lowered or re tracted position shown in Figures 1, 3 and 4.Fairing strips 24, of rubber or other suitable material and arcuate incross section, are secured to the sides of top frame member 11 withtheir lower portions resting upon the forward pontoons 20 in the loweredposition thereof, as shown in Figure 3. The fairing strips 24 providecontinuations of the rounded outer sides of pontoons 20, when the latterare lowered, and contribute to reduction of airor wind resistance in thetravel of the vehicle. The rearward pontoons 21 may be somewhat longerthan the forward pontoons 20, as shown, and are. similar thereto exceptthat they do not have extensions corresponding to the extensions 22 ofpontoons 20. The rearward ends of the rearward pontoons 21 are disposedin close proximity to the rearward bulkhead 14 and the outer sidesthereof are curved conformably to the side portions of tail member16 soas to merge smoothly therewith when pontoons 21 are in their lowered orretracted position. Fairing strips 25, similar to strips 24, are securedto the sides of the top frame member 11 and overlie the pontoons 21inthe same manner and for the same purpose as the fairing strips 24overlie the forward pontoons 20.

' When the pontoons are raised the fairing strips swing updegrees one tothe other.

ward, as indicated in broken lines in Figure 3. The pon toons 20 and 21,preferably are formed of light metal, such as aluminum, as are the nosemember 15 and the tail member 16.

Referring to Figures 1, 3 and 6, the rearward wall of each of theforward pontoons 20 is provided with two slot like pockets or recesses28 and 29 disposedradially of pivot rod 18 and at an angle ofapproximately ninety The recess 28 extends vertically from the top of.pontoon 20 and the recess 29 extends horizontally from the inner side ofextension 22 of pontoon 2.0, when the pontoons are in their lowered orretracted position shown. A blade-like latch bolt 30, approximatelyU-shaped in plan, is slidably mounted on pivotrods 18 by means ofsleeves 31 secured to bolt 30. The bolt 30 straddles a tubular housing32, to be .referred to more fully presently, and is urged rearward by acompression spring 33 confined between the housing 32 and a bridgingplate 34 secured, conveniently by welding, to the rearward ends of thearms of bolt 30,

3 plate 34 having a forwardly extending hollow boss 35 in which spring33 seats. When the forward pontoons are lowered the recesses 29 thereofare disposed in horizontal alignment in the same horizontal plane as thelatch bolt 30. If bolt 30 is then moved to its forward or projectedposition, it engages in the recesses 29, effective for positivelylocking the forward pontoons in lowered or retracted position, as shown.In like manner, when the forward pontoons 20 are in their fully extendedor raised positions, indicated in broken lines in Figure 3, the recesses28 are aligned in the horizontal plane of the latch bolt 30 which, ifprojected, engages in recesses 28 positively locking pontoons 20 raised.The rearward pontoons 21 are fixed on pivot rods 18, as previouslynoted, in the same angular relation thereto as the forward pontoons 20.Accordingly, locking the forward pontoons 20 in either raised or loweredposition also serves to lock the rearward pontoons 21 in the sameposition, as will be understood from what has been said.

Plate 34 is provided with a central rearwardly extending finger 38 towhich are pivoted the forward ends of two rearwardly diverging togglelinks 39. The rearward ends of links 39 seat on the outer faces of theforward ends of two links 40 pivoted at their rearward ends on the lowerend of a bracket 41 secured to the under face of top frame member 11.The overlapping ends of the links 39 and 40 are pivoted together bystuds 42 extending from opposite sides of the lower end of a rod 43slidable through top frame member 11. A knob 44 is secured on the upperend of rod 43 and in the lowered position thereof seats on a raised boss45 on the upper face of top frame member 11, so as to be readilygrasped. When rod 43 is in its lowered position, the toggle comprisingthe links 39 and 40 is extended and the latch bolt 30 is projected intothe recesses 28 or 29, as the case may be, for locking the pontoons inposition in the manner above described. Raising rod 43 breaks the toggleand latch bolt 30 is then moved rearward by compression spring 33releasing the pontoons for movement thereof from raised to loweredposition or vice versa. Normally, the rod 43 is in lowered position withthe pontoons locked in position and it is raised to release the pontoonsto permit change in position, as will be explained more fully later,preferably being returned to lowered position only when the pontoons arein either fully raised position or fully lowered position.

The rod 43 and knob 44 preferably are disposed adjacent the front of asuitable seat 48, which may be similar to a motor-cycle seat,appropriately secured to the top frame member 11. The tubular housing 32extends through the top and bottom members 11 and 12 of frame 10 towhich it is bolted, being provided for that purpose with upper and lowerbolting flanges 49 and 50. A collar 51, provided with a rearwardextension 52 substantially rectangular in plan, is secured-on housing 32at about the midheight of frame 10. Two upwardly and forwardly inclinedfoot rests or pedals 53 are pivoted at their forward ends, by means oflaterally projecting studs 54, on extension 52 of collar 51 at oppositesides thereof and are spaced outward from the sides of frame 10. Thepedals 53 are pivoted adjacent their rearward ends to side plates 55,secured to the sides of'frame 10 and extending a material distanceupward from the bottom thereof, by studs 56 projecting therefrom andreceiving pins 57 selectively insertible through a series of openings 58in the respective plates 55-concentric with the pivot axis of stud 54.That providesmeans whereby the inclination of pedals may be adjusted asdesired,

within limits, as will be understood from what has been said.

The tubular housing 32 extends downward a substantial distance belowframe 10. A motorunit 61 of known type, conveniently an outboard motor,is rotatably mounted on and extends downwardly through the housing 32.The unit 61 comprises the engine head 62, rotatably mounted on the upperend of housing 32, and a motor support tube 63 extending downwardthrough housing 32 and freely turnable therein. Support tube 63 extendsbelow housing 32 and is provided at its lower end with a gear housing 64carrying a propeller 65 and a steering rudder 66. The propeller 65 isdriven in a known manner and steering is effected by turning motor unit61 in appropriate directions about the axis of support tube 63. To thatend, handle bars 67 are secured to the sides of head 62 and extendrearwardly therefrom so as to be readily grasped by a rider occupyingseat 48. Conveniently suitable motor control means (not shown), forcontrolling the speed of travel of the vehicle, may be mounted on one ofthe handle bars 67 for ready accessibility.

The housing 32 extends downward a substantial distance below frame 10and has mounted thereon a plurality of upwardly and forwardly inclinedforward hydrofoils 70, 71 and 72. The lowermost hydrofoil 72 preferablyis provided with depending side flanges 73 of appreciable heightfunctioning as keel means provid ing a stabilizing effect for steering.A tubular rearward support 74 similar to housing 32 is bolted to andextends downward from bottom frame member 12. Preferably support 74extends upwardly into frame 10 and is suitably secured at its upper end,conveniently by welding, to a tubular cross brace member 75 extendingbetween and welded to the side plates 55. An inclined brace 76 is boltedat its forward end to the bottom frame member 12 and is suitably securedat its rearward end, conveniently by welding, to the cross brace member75. A plurality of rearward hydrofoils 77, 78 and 79, inclined upwardlyand forwardly, are mounted on support 74. The lowermost hydrofoil 79 isprovided with depending side flanges 80 of appreciable heightfunctioning as keel means to assist in steering.

When the device or vehicle attains comparatively high speeds of travelthe hydrofoils become effective for raising the body clear of the water,the vehicle then being supported by and travelling upon the hydrofoils.At comparatively low speeds of travel, or when the vehicle is at astandstill, the body is submerged in the water and is then supported byand travels upon the pontoons. At low speeds the pontoons 20 and 21extend outward from the body at right angles thereto, as in Figure 2 andas indicated in broken lines in Figure 3, and are locked in thatposition in the manner above described. That guards against swingingdown of the pontoons when banking on turns and objectionableinterference with turning. As the speed of travel increases, the body ofthe vehicle is raised out of the water. When that occurs, the pontoons20 and .21 are released by pulling rod 43 upward. The pontoons then dropby gravity to their lower or retracted positions shown in Figures 1 and3, in which they merge smoothly with the nose member 15 and the tailmember 16, so reducing wind resistance to a minimum as above explained,and are locked in that position by the latch means. The locking of thepontoons 20 and 21 in retracted position is particularly important asguarding against outward swinging and dipping into the water of thepontoons when banking in making sharp turns at high speed. The pontoons,in either of the two positions thereof shield the operator, toconsiderable extent, from spray and wind, particularly at the higherspeeds of travel with the pontoons retracted.

' In view of the fact that the forward pontoons 20 when retracted aredisposed in back of the nose member 15 and shielded thereby, it isdesirable that means he provided for initiating outward movement of thepontoons as the body of the vehicle is lowered into the water incidentto reduction in speed of travel thereof. Each of the forward pontoons 20has the forward lower area or portion 23a of its inner wall 23 inclinedforwardly and outwardly lengthwise and upwardly and inwardlytransversely, considering the pontoons 20 in their lowered or retractedposition.

When pontoons 20 are fully lowered or retracted, portions 23a of walls23 thereof define with the side plates 55 rear-wardly and upwardlytapering passages '83 opening at: the front of pontoons 20, as shown inFigures 3, 4 and 5. The side portions of nose member 15 are offsetupwardly to provide spaces 84, shown more clearly in Figures l. and 4,into which the forward ends of passages 8-3 open at opposite sides of acentral bottom portion 85 of nose member 15 constituting a continuationof the bottom frame member 12. When the vehicle sinks into the water atthe termination of a high speed run, incident to a reduction in speed,the latch bolt 30 is retracted releasing the pontoons 20. As the body ofthe vehicle enters the water, still travelling at moderately high speed,the water flows through spaces 84 and into the passages 83, as indicatedby the full line arrows in Figure 3. The water entering passages 83 atsubstantial velocity exerts considerable upward and outward pressureagainst portions or areas 23a of pontoons 20 effective for swinging thelatter upward and outward beyond the sides of nose member 15.Thereafter, in the continued travel of the vehicle at reduced speed, thewater pressure on portions or areas 23a of pontoons 20 swings the lattera further distance outward and upward until the body of the vehicle issubmerged, at which time the pontoons 20 and 21 are in full raised orextended position, in which they are then locked by pressing rod 43downward and thereby projecting latch bolt 30 into the aligned recesses29 in the forward pontoons 20. Preferably two cross bafiles 86, shownmore clearly in Figures 1, 3 and 4 are secured, conveniently by welding,between side plates 55 adjacent and at opposite sides of the tubularhousing 32.. The baflles 86 impart desirable rigidity to plates 55 tobetter resist the water pressure to which they are subjected.

It will be understood that changes in detail may be resorted to withoutdeparting from the field and scope of my invention, and I intend toinclude all such variations: as fall within the scope of the appendedclaims, in this application in which the preferred form only of myinvention has been disclosed.

I claim:

1i. In an aquatic device of the character described, a body comprisingan elongated substantially rectangular flat sided frame generally oblongin plan and of slight width relative to its length, a substantiallysegmo-spherical nose member secured to the front of said frame andextending beyond the sides thereof, motor means mounted on said framefor propelling said body, supports secured to and extending downwardbeyond said frame, hydrofoils mounted on said supports effective forraising said body out of the water when travelling at comparatively highspeed, and pontoons at opposite sides of said frame adjacent said nosemember and pivotally mounted at their upper portions for swingingmovements about axes substantially parallel with said frame, saidpontoons being of a generally segmo-cylindrical cross sectioncorresponding approximately to the respective portions of said nosemember extending beyond the sides of said frame, said pontoons havingflat inner side faces substantially conforming to the sides of saidframe and being movable downward and inward toward said frame into closeproximity thereto when said body is raised out of the water and movableupward and outward away from said frame to positions substantiallyperpendicular thereto when said body frame is submerged, said pontoonswhen in fully lowered position at the sides of said frame providingtherewith and with said nose member a structure of substantiallycircular cross section having a rounded nose.

2. In an aquatic device of the character described, a body comprising anelongated substantially rectangular frame generally oblong in plan andof slight width relative to its length, a substantially segmo-sphericalnose member secured to the front of said frame and extending beyond thesides thereof, a substantially segmo-spherical tail member secured tothe rear of said frame and extending beyond the sides thereof,motormean's attached to said frame for propelling said body, supportssecured to and extending downward beyond said frame, hydrofoils. mountedon said supports efi'ective'for raising said body out of the water whentravelling at comparatively high speed, forward pontoons at oppositesides of the forward portion of said frame adjacent said nose member andpivotally mounted at their upper portions for swinging movements aboutaxes substantially parallel with said frame, and rearward pontoons atopposite sides of the rearward portion of said frame adjacent said: tailmember and pivotally mounted at their upper portion for swingingmovements about axes substantially parallel with said frame, saidforward pontoons being of a generally segmocylindrical cross sectioncorresponding approximately to the respective portions of said nosemember extending beyond the sides of said frame and said rearwardpontoons being of a generally segmo-cylindrical crosssectioncorresponding approximately to the respective portions of saidtail member extending beyond the sides of 'said frames, said forward andrearward pontoons being movable downward toward said frame to positionsexterior thereof and in close proximity thereto when said body is raisedout of the water and movable upward and outward away from said frame topositions substantially perpendicula-r thereto when said body issubmerged, said rearward pontoons being spaced rearwardly from saidforward pontoons providing therebetween leg space for a person seated onthe top of said frame.

3. In an aquatic device of the character described, a body comprising anelongated substantially rectangular frame generally oblong in, plan andof slight width relative to its length, a substantially segmo-sphericalnose member secured to the front of said frame and extending beyond thesides thereof, motor means attached to the frame for propelling saidbody, supports secured to and extending downward beyond said frame,hydrofoils mounted on said supports effective for raising said body outof the water when travelling at comparatively high speed, and pontoonsat opposite sides of said frame adjacent said nose member and pivotallymounted at their upper portions for swinging movements about axessubstantially parallel with said frame, said pontoons being of agenerally segmo-cylindrical cross section corresponding approximately tothe respective portions of said nose member extending beyond the sidesof said frame, said pontoons having flat inner side faces and beingmovable downward and inward of said frame into close proximity theretowhen said body is raised out of the water and movable upward and outwardaway from said frame to positions substantially perpendicular theretowhen said body is submerged, the forward portions of the inner sidewalls of said pontoonsbeing inclined outwardly and forwardly lengthwisethereof and inwardly transversely thereof providing rearwardly andupwardly converging passages open at their forward ends at oppositesides of said frame when said pontoons are lowered, the side portions ofsaid nose member being offset upwardly providing spaces aligned withsaid passages for admission of water thereto to assist in raising saidpontoons.

4. In an aquatic device of the character described, a body comprising anelongated substanitally rectangular frame generally oblong in plan andof slight width relative to its length, side walls secured to said frameextending upward a material distance from the bottom thereof, asubstantially segmo-spherical nose member secured to the front of saidframe and extending beyond the sides thereof, motor means attached tothe frame for propelling said body, supports secured to and extendingdownward beyond said frame, hydrofoils mounted on said supportseffective for raising said body out of the water when travelling atcomparatively high speed, and pontoons at opposite sides of said frameadjacent said nose member and pivotally mounted at their upper portionsfor swinging movements about axes substantially parallel with saidframe, said pontoons being of a generally segmo-cylindrical crosssection corresponding approximately to the respective portions of saidnose member extending beyond the sides of said frame, said pontoonsbeing movable downward and inward of said frame into close proximitythereto when said body is raised out of the water and movable upward andoutward away from said frame to positions substantially perpendicularthereto when said body is submerged, the forward portions of the innerside walls of said pontoons being inclined outwardly and forwardlylengthwise thereof and inwardly transversely thereof defining with saidside walls rearwardly and upwardly converging passages open at theirforward ends at opposite sides of said frame when said pontoons arelowered, the side portions of said nose member being offset upwardlyproviding spaces aligned with said passages for admission of waterthereto to assist in raising said pontoons.

5. In an aquatic device of the character described, a body comprising anelongated substantially rectangular frame of slight width relative toits length and adapted to be straddled by the operator, two forward andtwo rearward pontoons at opposite sides of said frame pivoted thereonand movable downward and inward toward said frame to positions exteriorthereof and in close proximity to the sides of said frame when said bodyis raised out of the water and movable upward and outward away from saidframe to positions substantially perpendicular thereto when said body issubmerged, said forward pontoons being spaced from said rearwardpontoons providing therebetween leg space for an operator seated on saidframe, motor means attached to said frame adjacent said forwardpontoons, and means for raising said body out of the water whentravelling at comparatively high speeds, said forward pontoons whenlowered shielding the operators legs.

6. In an aquatic device of the character described, a body comprising anelongated substantially rectangular frame of slight width relative toits length and adapted to be straddled by the operator, two forward andtwo rearward pontoons of generally segmo-cylindrical cross section atopposite sides of said frame pivoted thereon and movable downward andinward toward said frame to positions exterior thereof and in closeproximity to the sides of said frame when said body is raised out of thewater and movable upward and outward away from said frame to positionssubstantially perpendicular thereto when said body is submerged, saidforward pontoons being spaced from said rearward pontoons providingtherebetween leg space for an operator seated on said frame, motor meansattached to said frame adjacent said forward pontoons, and means forraising said body out of the water when travelling at comparatively highspeeds, said forward pontoons when lowered shielding the operators legs.

7. In an aquatic device of the character described, a body comprising anelongated substantially rectangular frame of slight width relative toits length and adapted to be straddled by the operator, two forward andtwo rearward pontoons at opposite sides of said frame pivoted thereonand movable downward and inward toward said frame to positions exteriorthereof and in close proximity to the sides of said frame when said bodyis raised out of the water and movable upward and outward away from saidframe to positions substantially perpendicular thereto when said body issubmerged, said forward pontoons being spaced from said rearwardpontoons providing therebetween leg space for an operator seated on saidframe, a motor mounted on top of said frame for turning movementadjacent said forward pontoons and having a propeller and a steeringrudder for propelling and steering said body, an operators seat mountedon said frame adjacent said rearward pontoons, handle bars attached tosaid motor and extending rearwardly toward seat for steering said body,and means for raising said body out of the water when travelling atcomparatively high speeds, said forward pontoons when lowered shieldingthe operators legs.

8. In an aquatic device of the character described, a body comprising anelongated substantially rectangular frame of slight width relative toits length and adapted to be straddled by the operator, two forward andtwo rearward pontoons at opposite sides of said frame pivoted thereonand movable downward and inward toward said frame to positions exteriorthereof and in close proximity to the sides of said frame when said bodyis raised out of the water and movable upward and outward away from saidframe to positions substantially perpendicular thereto when said body issubmerged, said'forward pontoons being spaced from said rearwardpontoons providing therebetween leg space for an operator seated on saidframe, a motor mounted on top of said frame for turning movementadjacent said forward pontoons and having a propeller and a steeringrudder for propelling and steering said body, an operators seat mountedon said frame adjacent said rearward pontoons, foot rests mounted onsaid frame at the sides thereof in the space between said forward andrearward pontoons, handle bars attached to said motor and extendingrearwardly toward said seat for steering said body, and means forraising said body out of the water when travelling at comparatively highspeeds, said forward pontoons when lowered shielding the operators legs.

References Cited in the file of this patent UNITED STATES PATENTS1,084,578 Hewitt Jan. 13, 1914 1,100,044 Alexovic June 16, 19141,237,175 Cook Aug. 14, 1917 1,371,139 Banaszak Mar. 8, 1921 1,835,618Waller Dec. 8, 1931 2,451,781 Steele Oct. 19, 1948 2,550,220 Bussei Apr.24, 1951 FOREIGN PATENTS 46,851 France Aug. 4, 1936 (Addition to No.795,223) 476,479 Italy Dec. 12, 1952

